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Question: 1
Mention the types of chromosomes due to centromeric position.
Answer: 1
1-62There are four types of chromosomes.
i) Metacentric ii)Sub Metacentric iii)Acrocentric iv)Sub Acrocentric.
i) Metacentric ii)Sub Metacentric iii)Acrocentric iv)Sub Acrocentric.
Question: 2
Differentiate between chromosome and nucleosome.
Answer: 2
2-62Chromosome: Chromosome are thread like structures which appear inside the nucleus at the time of cell division. They are.composed of DNA and protein. They carry the genes on them.
Question: 3
Define Euchromatin.
Answer: 3
3-62The part of DNA is expressed time to time and condensed only during the cell division is called euchromatin. This coiling helps in movement of chromosomes during cell division.
Question: 4
What are nucleotides?
Answer: 4
4-62Nucleotide is structural unit of DNA. It composed of nitrogenous base,pentose sugar and phosphate group.
Question: 5
Compare telocentric and acrocentric chromosomes.
Answer: 5
5-62Telocentric Chromosomes:Telocentric has centromere at one end and chromatid part is present at other end.
Question: 6
What is nucleosome? Or Define nucleosome.
Answer: 6
6-62The DNA duplex is coiled around eight histone proteins forming a complex known as a nucleosome. It appears like beads on a string.
Question: 7
Give chromosomal theory of inheritance.
Answer: 7
7-62According to this theory,genes are located on chromosomes. At the time of cell division all the genes which are present on a chromosome,will go to same cell in which cell chromosome is transported.
Question: 8
How many chromosomes are present in mouse and sugar cane?
Answer: 8
8-62Sugar can has 80 while mouse has 40 chromosomes respectively.
Question: 9
Differentiate between heterochromatin and euchromatin.
Answer: 9
9-62Heterochromatin:Highly condensed part of chromatin is called heterochromatin. This part remains permanently condensed and never be expressed.
Question: 10
Define transformation. Name the scientist who worked upon it?
Answer: 10
10-62When the DNA of donor is transferred into recipient cell it brings changes into genetic material of the recipient cell, It is called transformation. Fredrick Griffth first of all performed experiments on it.
Question: 11
What is transformation?
Answer: 11
11-62When DNA of donor cell is inserted into recipient cell it changes the genetic material of recipient cell,this process is called transformation.
Question: 12
What is contribution of Erwin chargaff with respect to chemical nature of DNA?
Answer: 12
12-62He formulated chargaff rule. He proposed that ratio of purines is equal to pyrimidines and ratio of adenine and thymine is equal to guanine and cytosine.
A+T=G+C
A+T=G+C
Question: 13
What is phosphodiester linkage?
Answer: 13
13-62The reaction between the phosphate group of one nucleotide and the hydroxyl group of another is dehydration synthesis,eliminating water molecule and forming a covalent bond that links the two groups is called phosphodiester bond.
Question: 14
Give the functions of the DNA polymerase III.
Answer: 14
14-62DNA polymerase III progressively threads the DNA through the enzyme complex,moving at rapid rate,some 1000 nucleotides/second.
Question: 15
Briefly describe replication of lagging strand of DNA.
Answer: 15
15-62Lagging strand replicates away from the replication fork. It is synthesized discontinuously as a series of short segments that are later connected.These fragments are called Okzaki fragmernts.
Question: 16
What is gene?
Answer: 16
16-62The sequence of nucleotides that determines the amino acid sequence of a protein is called gene.
Question: 17
Differentiate between pyrimidines and purines.
Answer: 17
17-62Pyrimidines: Pyrimidines are nitrogenous bases present in nucleic acids,having only single ringed structure which is only six cornered.
Examples: Cytosine,Thymine and uracil.
Examples: Cytosine,Thymine and uracil.
Question: 18
Differentiate between semi conservative replication and conservative replication.
Answer: 18
18-62Semi Conservative Replication: The two strands of double helix of DNA separate out acting as a model or template,along which new nucleotide are arranged thus giving rise to two new DNA duplexes.
Question: 19
Define leading and lagging strand of DNA.
Answer: 19
19-62Lagging strand is that strand of DNA which is discontinuously synthesized while the strand of DNA which is continuously synthesized is called leading strand.
Question: 20
What is phosphodiester bond? How it is formed?
Answer: 20
20-62The reaction between phosphate group of one nucleotide and hydroxyl group of another is a dehydration synthesis,eliminating a water molecule and forming a covalent bond between two groups. This linkage is called a phosphodiester bond.
Question: 21
Differentiate between conservative and dispersive replication of DNA.
Answer: 21
21-62Conservative Replication: Conservative replication stated that the parental strands would remain intact and generate DNA copies consisting of entirely new molecules.
Question: 22
Differentiate between template and coding stands of DNA.
Answer: 22
22-62Template Strand: The strand of DNA which is transcribed is called template strand or antisense strand.
Question: 23
What are Okazaki fragments? Also give their length.
Answer: 23
23-62During replication of DNA,one of its strands is discontinuously synthesized in the form of fragments called Okazaki fragments.Its length in eukaryotes is 100 to 200 nucleotides while in prokaryotes it is 1000 to 2000 nucleotides.
Question: 24
Write role of DNA ligase.
Answer: 24
24-62The function of DNA ligase is to fill the nicks (small gaps) or to join the Okazaki fragments to make a continuous strand of DNA.
Question: 25
Differentiate between transcription and translation.
Answer: 25
25-62Transcription: it is the first step of protein synthesis,in transcription mRNA is synthesized from DNA.
Question: 26
Define sense & antisense strands of DNA?
Answer: 26
26-62The strand of DNA which is transcribed is called template or antisense strand and the opposite strand is called sense strand.
Question: 27
Define central Dogma.
Answer: 27
27-62Central Dogma means all the organisms use the same basic mechanism of gene expression which is referred to as Central Dogma.
Question: 28
Define transcription.
Answer: 28
28-62Syntheis of mRNA from the DNA is called transcription.It is first step of central dogma.
Question: 29
Give the chemical composition of RNA.
Answer: 29
29-62RNA is composed of nitrogen bases (adenine.guanine,cytosine and uracil),pentose sugar(ribose) and phosphate group.
Question: 30
What is tRNA? Give its role.
Answer: 30
30-62tRNA is a type of RNA which is 70 to 90 nucleotides in length. It transfers amino acids during the protein synthesis to the place where protein is synthesized in the cell.
Question: 31
What is transcription bubble? How is it formed?
Answer: 31
31-62The DNA strand open at specific place where enzyme is attached to the template strand forming transcription bubble.
Question: 32
What is central Dogma? Give its two steps.
Answer: 32
32-62All organisms use the same basic mechanism of reading and expressing the genes,which is often referred to as central dogma.First step of central dogma is transcription and second step is translation (synthesis of protein from mRNA).
Question: 33
Name types of RNA.
Answer: 33
33-62There are three types of RNA,which are named as
Question: 34
What is role of promoter is transcription?
Answer: 34
34-62Promoter is responsible for the correct initiation of transcription process.
Question: 35
What is function of RNA polymerases in transcription?
Answer: 35
35-62The function of RNA polymerases are as
Question: 36
How is newly synthesized mRNA protected after transcription?
Answer: 36
36-62A cap and tail is added so that molecule may remain stable during its travelling to cytoplasm. The cap is in the form of 7-methyl GTP where as tail is in the form of poly A tail linked to 3 end of the RNA.These cap and tail protects RNA from action of enzymes.
Question: 37
What is universality of genetic code?
Answer: 37
37-62It mean it is same for all the organisms.Because of the universality of codon the genes can be transferred from one organism to another and successfully transcribed and translated in their new host.
Question: 38
Differentiate between codon and anticodon.
Answer: 38
38-62Codon: Codon is sequence of three nucleotides present on mRNA and specifies an amino acid.
For Example codon for methionine is AUG.
For Example codon for methionine is AUG.
Question: 39
Define genetic code.
Answer: 39
39-62Genetic code is combination of three nucleotides,which specify a particular amino acid.
Question: 40
Define phenylketonuria. OR What is phenylketonuria?
Answer: 40
40-62In phenylketonuria,phenylalanine is not degraded because of defective enzyme phenylalanine hydroxylase. Phenylalanine consequently accumulates in the cells leading to mental retardation,as the brain cells fails to develop in infancy.This disorder is due to point mutation.
Question: 41
What is meant by promoter?
Answer: 41
41-62A specific nucleotide sequence to which RNA polymerase attaches and initiate transcription of mRNA from a gene.
Question: 42
Enlist non sense codons and their function.
Answer: 42
42-62Non sense condons do not specifiy any amino acid. They are used to terminate or to stop the protein synthesis.Their names are UAA,UGA and UGA.
Question: 43
Enlist initiation codon and non-sense codons.
Answer: 43
43-62Initiation codon is Aug and non sense condons are UAA,UAG and UGA.
Question: 44
Differentiate between transcription and replication.
Answer: 44
44-62Transcription: Transcription is the process in which RNA is synthesized from DNA.
Question: 45
Define initiation codon. What does it codes for?
Answer: 45
45-62Initiation codon is first codon in the process of protein synthesis from where protein synthesis starts.It codes for methionine.
Question: 46
How is translation terminated?
Answer: 46
46-62When a chain terminating non sense codon is exposed,this non sense codon do not bind any tRNA but they are recognized by release factor,protein that release the newly made polypeptide from the ribosome.
Question: 47
Define genetic code.Give its properties.
Answer: 47
47-62Genetic code is combination of three nucleotides,which specify a particular amino acid.
Question: 48
What is translation? Or Define translation.
Answer: 48
48-62Synthesis of protein from the mRNA is called translation.It is second step of central dogma.
Question: 49
Define Mutation.
Answer: 49
49-62The sudden change in DNA or gene is called mutation.
Question: 50
What is mutation? Give its name of two classes.
Answer: 50
50-62Changes in the DNA occur either due to mistake in replication or damage to the genetic message is known as mutations. its classes are:
1- Point mutations 2- Chromosomal aberrations.
1- Point mutations 2- Chromosomal aberrations.
Question: 51
What is Semi-Conservative Model of DNA Replication?
Answer: 51
51-62In semi conservative replication,the two strands of the duplex separates out each acting as a model or mold,along which new nucleotides are arranged thus giving rise to two new duplexes.In this process,by separation of two strands,primary structure has been conserved, whereas the secondary structure has been disrupted.
Question: 52
How many chromosomes are found in ferns and in Frog?
Answer: 52
52-62Number of chromosomes found in ferns are more than 500 pairs.
Number of chromosomes found in frog are 26.
Number of chromosomes found in frog are 26.
Question: 53
Describe chromosomal aberrations.
Answer: 53
53-62Chromosomal aberrations are mega changes which involve presence of an extra chromosome or loss of a chromosome from the diploid number of chromosomes or changes like addition,insertion,inversion and duplication.
Question: 54
What is the difference between R, and S, type of bacteria?
Answer: 54
54-62R From: The mutant from of streptococcus pneumoniae bacteria,which lacks an enzyme needed to manufacture the polysaccharide coat is called the R form because it forms R colonies.On growth medium.
Question: 55
What is one-gene one polypeptide hypothesis?
Answer: 55
55-62Beadle and tatum concluded that genes produce their effects by specifying the structure of enzymes and that each gene encodes the structure of one enzyme.They called this relationship one-gene/one-enzyme hypothesis.
Question: 56
What is point mutation? Give two examples.
Answer: 56
56-62Point mutation are mutational changes that affects the message itself,producing alterations in the sequence of DNA nucleotides. If alteration involves mutations.For example sickle cell anemia and phenylketonuria.
Question: 57
What are chromosomal aberrations? Give its reasons.
Answer: 57
57-62Unequal distribution of chromosomes in daughter cell during cell division or any change in the structure of chromosome leads to abnormalities in chromosome in daughter cell,it is called chromosomal aberration.
Question: 58
what is a phosphodiester bond?
Answer: 58
58-62The reaction between the phosphate group of one nucleotide and the hydroxyl group of another is a dehydration synthesis,eliminating a water molecule and forming covalent bond that links the two groups.The linkage is called a phosphodiester bond.
Question: 59
What are mutagens? Give one example.
Answer: 59
59-62In genetics,a mutagen is a physical or chemical agent that changes the genetic material,usually DNA of an organism and thus increases the frequency of mutations.
For Example: X-ray,ultraviolet radiations etc.
Question: 60
How many DNA polymerases are found in prokaryotes? Write their names.
Answer: 60
60-62There are three DNA polymerases namely I,II and III in bacteria.
i) DNA polymerase I ii) DNA polymerase II iii) DNA polymerase III
i) DNA polymerase I ii) DNA polymerase II iii) DNA polymerase III
Question: 61
Where codon and anticodon are situated?
Answer: 61
61-62Codon are situated on mRNA(messenger RNA) while anticodon are situated on tRNA(transfer RNA).
Question: 62
Differentiate between sense and anti sense strands of DNA.
Answer: 62
62-62Sense strand; The strand of DNA which is opposite to the antisense strand and is not transcribe is known as sense strand or coding strand.